This invention relates to a method for manufacturing a charge control agent including an azo-type metal complex having an ammonium ion of a counter ion, which is used for a toner for developing an electrostatic image or a powder paint.
An electrophotography system applied to a copy machine, printer or facsimile performs to develop an electrostatic latent image on a photosensitive frame by toner having frictional electrification, and to transfer and then fix the imaged toner onto a paper.
A charge control agent is added to the toner beforehand so as for the toner to quicken a rise speed of the electrification, electrify sufficiently, control a proper quantity of the electrification stably, improve electrification property, rise up a speed for developing the electrostatic latent image, and form the vivid images.
For instance, as the charge control agent, azo-type metal complex salts are mentioned in Japanese Patent Provisional Publication No. 61-155464.
The copy machine or the printer brings lately about high efficiency with improving resolution and so on. The electrophotography system is used for not only a high speed development but also a low speed development, as purposes are expanded. Therefore, it is required that the charge control agent causes the faster rise speed of the electrification of the toner and excellent electrification property and is able to form the vivid images of high resolution. And it is required that the charge control agent is able to be used for a powder paint for a electrostatic powder printing method which the powder paint is attracted and baked onto a surface of a frame-work having a charge, and causes excellent electrification properties.
The charge control agent including the azo-type metal complex salt having an ammonium counter ion with only a low content causes insufficiently electrification properties.
It is desired the charge control agent including the azo-type metal complex salt having the ammonium counter ion with the high content so as to improve the electrification properties much. Nevertheless it was difficult to manufacture the charge control agent with the high content at high purity.